Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Forest

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on Simic Ascendancy.
At the beginning of your upkeep, if Simic Ascendancy has twenty or more growth counters on it, you win the game.

Followed Footsteps

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature.

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Mizzium Skin

Target creature you control gets +0/+1 and gains hexproof until end of turn.
Overload {1}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Temple of Mystery

Temple of Mystery enters the battlefield tapped.
When Temple of Mystery enters the battlefield, scry 1.
{T}: Add {G} or {U}.

Spark Double

You may have Spark Double enter the battlefield as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Metamorphic Alteration

Enchant creature
As Metamorphic Alteration enters the battlefield, choose a creature.
Enchanted creature is a copy of the chosen creature.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Soul Foundry

Imprint — When Soul Foundry enters the battlefield, you may exile a creature card from your hand.
{X}, {T}: Create a token that's a copy of the exiled card. X is the mana value of that card.

Rhys the Redeemed

{2}{G/W}, {T}: Create a 1/1 green and white Elf Warrior creature token.
{4}{G/W}{G/W}, {T}: For each creature token you control, create a token that's a copy of that creature.

Roalesk, Apex Hybrid

Flying, trample
When Roalesk, Apex Hybrid enters the battlefield, put two +1/+1 counters on another target creature you control.
When Roalesk dies, proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

Island

Clever Impersonator

You may have Clever Impersonator enter the battlefield as a copy of any nonland permanent on the battlefield.

Stolen Identity

Create a token that's a copy of target artifact or creature.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)

Soul's Attendant

Whenever another creature enters the battlefield, you may gain 1 life.

Tamiyo, Field Researcher

+1: Choose up to two target creatures. Until your next turn, whenever either of those creatures deals combat damage, you draw a card.
−2: Tap up to two target nonland permanents. They don't untap during their controller's next untap step.
−7: Draw three cards. You get an emblem with "You may cast spells from your hand without paying their mana costs."

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Imperious Perfect

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Copy Enchantment

You may have Copy Enchantment enter the battlefield as a copy of any enchantment on the battlefield.

Kiora's Follower

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token that's a copy of that creature that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Mirror Gallery

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Progenitor Mimic

You may have Progenitor Mimic enter the battlefield as a copy of any creature on the battlefield, except it has "At the beginning of your upkeep, if this creature isn't a token, create a token that's a copy of this creature."

Mirari's Wake

Creatures you control get +1/+1.
Whenever you tap a land for mana, add one mana of any type that land produced.

Replicate

Create a token that's a copy of target creature you control.

Repudiate

Counter target activated or triggered ability. (Mana abilities can't be targeted.)

Repudiate // Replicate

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Caged Sun

As Caged Sun enters the battlefield, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Kiora, the Crashing Wave

+1: Until your next turn, prevent all damage that would be dealt to and dealt by target permanent an opponent controls.
−1: Draw a card. You may play an additional land this turn.
−5: You get an emblem with "At the beginning of your end step, create a 9/9 blue Kraken creature token."

Thornweald Archer

Master Biomancer

Each other creature you control enters the battlefield with a number of additional +1/+1 counters on it equal to Master Biomancer's power and as a Mutant in addition to its other types.

Biovisionary

At the beginning of the end step, if you control four or more creatures named Biovisionary, you win the game.

Prophet of Kruphix

Untap all creatures and lands you control during each other player's untap step.
You may cast creature spells as though they had flash.

Parallel Lives

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Essence Warden

Whenever another creature enters the battlefield, you gain 1 life.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.